<template>
  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>

    <el-form label-width="120px">

      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>

      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类" @change="subjectLevelOneChanged">

          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>

        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
          <el-option
            v-for="subject in subjectTwoList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>


      <!-- 课程讲师 TODO -->
      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select v-model="courseInfo.teacherId" placeholder="请选择">
          <el-option v-for="teacher in teacherList" :key="teacher.id" :label="teacher.name" :value="teacher.id"/>
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <!-- 课程简介 TODO -->
      <el-form-item label="课程简介">
        <tinymce v-model="courseInfo.description" :height="300"></tinymce>
      </el-form-item>

      <!-- 课程封面 TODO -->
      <!-- 课程封面-->
      <el-form-item label="课程封面">

        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduoss/fileoss'"
          class="avatar-uploader">
          <img :src="courseInfo.cover">
        </el-upload>

      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/>
        元
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
  import course from "@/api/edu/course";
  import subject from "@/api/edu/subject";
  //引入富文本编辑器组件
  import Tinymce from "@/components/Tinymce"

  export default {
    components: {
      Tinymce
    },
    name: "info",
    data() {
      return {
        saveBtnDisabled: false,
        courseInfo: {
          title: '',
          subjectId: '',//二级分类id
          subjectParentId: '',//一级分类id
          teacherId: '',
          lessonNum: 0,
          description: '',
          cover: '/static/01.jpg',
          price: 0
        },
        BASE_API: process.env.BASE_API, // 接口API地址
        teacherList: [],//封装所有的讲师
        subjectOneList: [],//一级分类
        subjectTwoList: [],//二级分类
        courseId: ''//课程Id

      }
    },
    methods: {

      //添加课程信息
      addCourse() {
        course.addCourseInfo(this.courseInfo)
          .then(resp => {
            //提示
            this.$message({
              type: "success",
              message: '添加课程信息成功'
            })

            //跳转到第二步
            this.$router.push('/course/chapter/' + resp.data.courseId)
          })
      },
      //修改课程信息
      updateCourse() {
        course.updateCourseInfo(this.courseInfo)
          .then(resp => {
            //提示
            this.$message({
              type: "success",
              message: '修改课程信息成功'
            })
            //跳转到第二步
            this.$router.push('/course/chapter/' + this.courseId)
          })
      },
      saveOrUpdate() {
        //判断添加还是修改
        if(!this.courseInfo.id) {
          //添加
          this.addCourse()
        } else {
          this.updateCourse()
        }
      }
      ,
      //获取讲师列表
      getTeacherList() {
        course.getList()
          .then(resp => {
            // console.log(resp)
            this.teacherList = resp.data.items
          })
      }
      ,
      //查询所有一级分类
      getOneSubject() {
        subject.getAllSubject()
          .then(resp => {
            this.subjectOneList = resp.data.list
          })
      }
      ,
      //一级分类被点击
      subjectLevelOneChanged(value) {
        //这个模板框架封装了的value就是 当前点击的一级分类的id值
        // alert(value)
        for (let i = 0; i < this.subjectOneList.length; i++) {
          //当前点击的分类id 与一级分类id一样
          if (value === this.subjectOneList[i].id) {
            //把当前一级分类的二级分类赋值
            this.subjectTwoList = this.subjectOneList[i].children
            //把二级分类id清空
            this.courseInfo.subjectId = ''
          }
        }
      }
      ,

      //上传封面成功调用的方法
      handleAvatarSuccess(res, file) {
        this.courseInfo.cover = res.data.url
      }
      ,
      //上传封面之前的方法，规定文件类型和文件地址
      beforeAvatarUpload(file) {
        const isJPG = file.type === 'image/jpeg'
        const isLt2M = file.size / 1024 / 1024 < 2
        if (!isJPG) {
          this.$message.error('上传头像图片只能是 JPG 格式!')
        }
        if (!isLt2M) {
          this.$message.error('上传头像图片大小不能超过 2MB!')
        }
        return isJPG && isLt2M
      }
      ,

      //获取课程信息
      getInfo() {
        course.getCourseInfoId(this.courseId)
          .then(resp => {
            //在courseInfo课程基本信息，包含一级分类id和二级分类id
            this.courseInfo = resp.data.courseInfoVo

            //1.查询所有的分类，包含一级和二级
            subject.getAllSubject()
              .then(resp => {
                this.subjectOneList = resp.data.list
                for (let i = 0; i < this.subjectOneList.length; i++) {
                  //获得所有一级分类id
                  var subjectOneListElement = this.subjectOneList[i];
                  if (this.courseInfo.subjectParentId === subjectOneListElement.id) {
                    this.subjectTwoList = subjectOneListElement.children
                  }
                }
              })
          })
        //初始化所有讲师
        this.getTeacherList()
      }
      ,
      init() {
        if (this.$route.params && this.$route.params.id) {
          this.courseId = this.$route.params.id
          //回显当前课程信息
          this.getInfo()
        } else {
          //初始化所有讲师
          this.getTeacherList()
          //初始化一级分类
          this.getOneSubject()
          //清空信息
          this.courseInfo = {}
          //封面不清除
          this.courseInfo.cover = '/static/01.jpg'
        }
      }
    },
    created() {
      this.init()
    },
    watch: {
      //监听
      $route(to, from) { //路由变化方式，路由发生变化，方法就会执行
        this.init()
      }
    }
  }
</script>

<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
